US4852509A

US4852509A - Floating dock having shock-absorbing coupling

Info

Publication number: US4852509A
Application number: US07/232,296
Authority: US
Inventors: Sig T. Fransen; Wayne K. Dye, Jr.
Original assignee: Oregon Marine Floats Inc
Current assignee: Oldcastle Precast Inc
Priority date: 1988-08-15
Filing date: 1988-08-15
Publication date: 1989-08-01
Anticipated expiration: 2008-08-15
Also published as: CA1304631C

Abstract

A multi-element floating dock has shock-absorbing flexible tieing elements which are installed as a unit without any manual adjustment being required to create a pretensionin the shock-absorbing components. Elastomeric pads positioned in aligned cavities formed in the edges of the dock sections receive the ends of the flexible tieing elements. Stops located on the ends of the tieing elements engage the pads so that adjacent dock sections cannot be separated from one another without compressing the pads and thereby creating a compressibly yieldable restraint against the separation of the dock sections and preventing their being separated from one another past a predetermined limit. An elastomeric spacer located between adjacent dock sections provides a compressibly yieldable restraint against moving the dock sections toward one another and prevents them from coming closer to one another then a predetermined amount. Tension plates fit between the stops and the ends of the cavities to precompress the pads and the elastomeric joint is wider than the normal gap formed between the dock sections thereby requiring it to be precompressed when it is installed. A line-up sleeve located in the center of the cable is engaged by counterbores formed in the pads and by the ends of the cavities to prevent lateral and vertical movement between adjacent dock sections.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to multi-element floating docks, and in particular to such docks in which the dock sections are joined together with flexible shock-absorbing couplings.

It is a common practice to make docks for mooring boats and the like from a plurality of floating sections which are joined together end to end. These dock sections must be joined together in a manner which permits angular displacement between them in order to accommodate wave action and other movement of the dock. However, the dock sections must be prevented from moving laterally and vertically relative to one another in order to maintain alignment. In addition, while the amount of separation between the dock sections must vary somewhat if the dock sections are to accommodate wave action, the amount of this separation must be limited.

In the past dock sections have been joined together by spanning both sides of adjacent dock sections with elongate wood planks or whalers. Threaded rods are inserted through aligned openings in the dock sections and the whalers and nuts are secured to their ends to clamp the whalers to the dock sections. This system has several shortcomings which limit its usefulness. First, since the threaded rods extend through the entire dock sections they are unwieldly and subject to breakage. In addition, while wood whalers are somewhat flexible, they do not permit the unlimited rotational movement between adjacent dock sections which is necessary to accommodate heavy wave action. Furthermore, the nuts on the ends of the threaded rods must be tightened sufficiently to achieve proper clamping action and not work free and yet must not be overtightened to the point where they compromise the strength of the components. Accordingly, the people who install the nuts must be skilled, and even then some overtightening and undertightening will occur. Because the coupling elements are partially concealed by the dock sections it is difficult to inspect them for damage. Even more of a problem is that the marine environment in which docks of this type are used will cause the nuts to become rusted onto the threaded rods making them difficult to remove. A final shortcoming of this prior art system is that in order to use it to attach finger piers to a main dock section, flanges must be attached to the finger pier which increases the cost and requires the use of different coupling elements.

The subject invention overcomes the foregoing shortcomings and limitations of the prior art by using elongate, flexible, noncompressible tieing elements, such as cables, to couple adjacent dock sections together. The cables pass through openings in elastically compressible pads which are attached to the dock sections. The cables have stops located at each of their ends which engage the outer ends of the pads and prevent the cables from being pulled back out of the pads. Thus, the pads act as compressibly yieldable restraints against the separation of the dock sections and prevent their separation past a predetermined point. An elastically compressible spacer which fits between adjacent dock sections serves as a compressibly yieldable restraint against movement of the dock sections toward one another and prevents their being moved closer together than a predetermined amount.

In a preferred embodiment of the invention the pads are placed in steel-lined cavities which are formed in the top surfaces of adjacent dock sections, which generally are made from reinforced concrete. This permits the steel liners to be welded to the reinforcing bar in the dock sections which spreads the load carried by the coupling elements over a wide portion of the dock sections. The pads are separated into top and bottom portions which have semispherical grooves in their mating surfaces which receive the cables. Thus, the bottom portion of a pad can be positioned in the cavity, the cable placed on top of it, and then the top portion of the pad installed over the top of the cable.

Tension plates are inserted between the stops and the end walls of the cavities to precompress the pads and eliminate the free movement which would otherwise result from the clearance which is necessary to allow assembly of the components. In addition, the spacer which fits between the dock sections is wider than the nominal distance between the sections which causes this element to be precompressed also.

A line-up sleeve, which is attached to each cable intermediate its ends, fits into counterbores located in the ends of the pads and in openings formed in the end walls of the cavity. Thus, the line-up sleeve prevents lateral and vertical movement of the joined dock sections relative to one another without limiting the rotational movement necessary to accommodate wave action.

Accordingly, it is a principal object of the present invention to provide a multi-element floating dock having shock-absorbing flexible couplings which can be installed easily and quickly.

It is a further object of the present invention to provide such a dock in which the coupling elements are readily accessible for inspection.

It is a still further object of the present invention to provide such a dock in which the coupling elements are pretensioned automatically upon installation without the requirement of manual adjustment.

It is a still further object of the present invention to provide such a dock in which the coupling elements can be replaced easily without the necessity of loosening threaded connectors.

It is a yet a further object of the present invention to provide such a dock in which the same coupling components can be used for attaching main dock sections together and for attaching finger piers to the main dock sections.

The foregoing and other objectives, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, partially broken away to show hidden detail, of a multi-element floating dock embodying the present invention.

FIG. 2 is a plan view of the dock.

FIG. 3 is a fragmentary plan view, partially broken away to show hidden detail, at an enlarged scale showing that portion of the dock containing the elements which are used to couple adjacent dock sections together.

FIG. 4 is a sectional view taken along the line 4--4 of FIG. 3.

FIG. 5 is a sectional view, looking from above, showing details of a dock section.

FIG. 6 is a sectional view taking along the line 6--6 in FIG. 3.

FIG. 7 is a perspective view of a pad which is an element of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2 of the drawings, docks, such as used for mooring boats, often are constructed from a plurality of floating dock sections 10 which are tied together end to end. In addition, smaller dock sections 10a are attached to and extend out from the main dock sections to create finger piers to which the boats can be tied. The dock sections generally comprise inverted concrete shells having planar horizontal tops 12 and vertical side walls 14 which depend from the periphery of the tops. Styrofoam blocks 16 are placed under the shells to increase their buoyancy.

Referring now also to FIGS. 3 and 4, the dock sections have cavities 18 formed in their tops which carry the coupling elements which tie adjacent dock sections together. These cavities are located in each dock section next to the side wall which will abut the side wall of the adjacent dock section, and the cavities in adjacent dock sections are arranged in pairs which are aligned with one another. The cavities are lined with steel side walls 20, end walls 22, and bottom walls 24, with the outside end walls 22a preferably replacing a portion of the concrete side wall 14. The cavity walls do not extend completely to the top surface of the dock section but are recessed from it by a distance equal to the thickness of the cavity walls. The cavity walls preferably are cast into the dock section when it is formed in order to create an integral unit. In addition, referring to FIG. 5, the cavity walls are welded to the reinforcing bar 26 which is embedded in the concrete of the dock section thereby spreading the loads which act on the cavity walls through a large portion of the dock section.

The cavities are covered by access plates 28 which fit into the recess which is formed above the cavity walls. Referring now to FIG. 6, a slot 30, having an arcuate lower extremity is located in the top portion of each outside end wall 22a. A tab 32 which depends from one edge of each access plate fills the upper portion of the slot 30 when the access plate is placed over the cavity. The bottom of the tab 32 also is arcuate so that a circular opening is formed between the end wall and the tab.

Adjacent dock sections are connected to one another by elongate flexible tieing elements, such as cables 34, which fit into and are retained by the cavities 18. Each cable 34 has a sleeve 36 attached to each of its ends and stop plates 38 are attached to both sides of each sleeve. The stop plates 38 are rectangular and are dimensioned to fit snugly within the cavities 18. When it is placed in a cavity, the portion of the cable 34 which extends between the inner stop 38b and the end wall 22a is enclosed with an elastomeric pad 40. The pad 40 substantially fills the cavity and is divided into top and bottom portions. Thus, the bottom portion can be placed into the cavity first, the cable can then be placed into the bottom portion of the pad, and the top portion can then be placed on top of the cable. As can be seen in FIG. 7, the pad portions have semi-cylindrical grooves 42 formed in them which form a cylindrical opening for the cable when the pad portions are brought together. At one end of the pads the grooves are enlarged to form a larger diameter counterbore 44, whose use will be described later.

The length of the cable between the two inner stops 38b is greater than double the length of the pads by an amount which is equal to the desired distance between the adjacent pair of dock sections which are tied together by the cable. If the dock sections are forced further apart the inner stops engage the pads and cause them to become compressed. Thus, the pads act as yieldable restraints against further separation of the dock sections up to a point where the pads become totally compressed and no further separation is possible. In addition the length of the sleeve 36 is such that when the cable is installed in the pad there is a gap between the end wall 22 and the outer stop 38a. If a wedge (not shown) is driven between the adjacent dock sections the inner stops it will cause the pads 40 to become compressed and the gaps between the end walls 22 and the outer stops 38a will be made larger. Tension plates, having a width equal to this larger gap, can be inserted into the gaps and the wedge removed to precompress the pads 40. This procedure eliminates any unrestrained movement of the dock sections away from one another which otherwise would occur due to the clearance which is necessary to install the cable into the pads in the first instance.

After the pads have been precompressed by insertion of the tension plates 46, an extruded elastomeric spacer 48 is inserted between the adjacent dock sections. The spacer acts as a yieldable restraint against movement of the dock sections toward one another and prevents them from becoming closer together than a predetermined distance. The spacer has a rounded cap 50 which smoothes the transition between the top surfaces of the dock sections. The width of the spacer is slightly greater than the normal space between the dock sections. Accordingly, the dock sections must be forced apart to insert the spacer and the spacer becomes precompressed when it is installed. As with the precompression of the pads, precompression of the spacer eliminates any unrestricted movement of the dock sections toward one another due to the clearance which would otherwise be necessary in order to insert the spacer between them.

A line-up sleeve 52, similar to sleeves 36, is attached to the cable 34 intermediate its ends. The line-up sleeve 52 has the same diameter as the opening formed between the tabs 32 and the end walls 22a, and the counterbore 44 formed in the end of the pads. Thus, the line-up sleeve is engaged snugly by the pads and the end wall to prevent lateral and vertical movement of a dock section relative to the dock section to which it is attached. However, the flexible nature of the cable permits angular movement of the dock sections relative to one another in order to accommodate wave action on the dock.

When assembled the joint between the dock sections permits a predetermined amount of variation in either direction from the nominal amount of separation and yet does not permit movement past these predetermined limits. In addition, the dock sections are maintained in lateral and vertical alignment relative to one another at all times and yet angular movement is permitted to accommodate wave action. Furthermore, it is easy to inspect the joint elements to determine if they are damaged or have become worn beyond acceptable limits merely by lifting the access plates 28 off of the cavities.

Due to the fact that there are no elements which need to be tightened, the joint is easy to construct and the proper level of pretensioning is achieved automatically based on the size of the components. In addition, the lack of movable elements makes the joint easy to replace and rusting of the joint components will not impede their replacement. Finally, the joint components which attach main dock sections together can also be used to attach finger piers to the main dock sections.

The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.

Claims

What is claimed is:

1. A multi-element floating structure comprising:

(a) two or more floating dock sections which are positioned in end-to-end adjacency relative to one another;

(b) at least one elongate, flexible, noncompressible tieing element which extends between each adjacent pair of dock sections, said tieing element having a stop located proximate each of its ends;

(c) first elastically compressible means associated with each of said dock sections in each adjacent pair of dock sections and with said stops for exerting a compressibly yieldable restraint against the separation of the dock sections in each adjacent pair of dock sections relative to one another, and for preventing the dock sections in each adjacent pair of dock sections from being separated from one another by more than a first predetermined distance;

(d) second elastically compressible means located between each adjacent pair of dock sections for exerting a compressibly yieldable restraint against the movement of dock sections in each adjacent pair of dock sections toward one another and preventing the dock sections in each adjacent pair of dock sections from becoming closer than a second predetermined distance to one another;

(e) wherein said dock sections have cavities defined in the top surfaces thereof, with each cavity in every dock section being located proximate to and aligned with a mating cavity in an adjacent dock section, and said first elastically compressible means comprises an elastomeric pad which fits in said cavities and has an opening defined medially therethrough which receives said tieing element, said pad being separated into two pieces, one which fits into said cavity below said tieing element and one which fits into said cavity above said tieing element.

2. A multi-element floating structure comprising:

(e) first precompression means for precompressing said first elastically compressible means;

(f) wherein said sections have cavities defined in the top surfaces thereof, with each cavity in every dock section being located proximate to and aligned with a mating cavity in an adjacent dock section, and said first elastically compressible means comprises an elastomeric pad which fits in said cavities and has an opening defined medially therethrough which receives said tieing element, and said pad and said stop do not completely fill said cavity and said first precompression means comprises a tension plate which in combination with said pad and said stop completely fit into said cavity only when said pad is compressed.